Bis 101 Exam 1

Haploid

One copy of each chromosome

Diploid

Two copies of each chromosome

Polyploid

Three or more copies of each chromosome

How many chromosomes doe humans have?

2n = 46 chromosomes total. Every cell has two copies of each. Meaning if humans were haploid we would only have 23 chromosomes

What is a locus?

A region of interest along a DNA sequence or chromosome

Allele

different variants of a gene at the same locus

Genotype

The combination of alleles an organism has

What does it mean when something is homozygous?

The two alleles are the same variantW

What does it mean when something is heterozygous?

The two alleles are different

Phenotype

the observable characteristic of an organism, here what is being produced by the genotype

Chromosome

unit of DNA that has an array of genes, divides during mitosis/meiosis

Genome

all the chromosomes in an organism

How do genotypes produce phenotypes?

Gene expression is producing the end product of a gene. The central dogma: DNA is transcribed into RNA then RNA is translated into a protein

What usually determines the phenotype?

Proteins

How can you tell a trait is autosomal or sex linked on a pedigree?

A trait is autosomal dominant if the affected individuals have affected parents. It is autosomal recessive if the affected individuals have unaffected parents. A trait is X linked recessive if most of the affected individuals are XY.